According to recent figures from the World Health Organisation, in 2006 there were some 22,000 new HIV infections in Western and Central Europe. In total 740,000 people in the region are living with HIV.
Tracking the progress of those newly infected with HIV in Europe is the EU-funded CASCADE (Concerted Action on SeroConversion to AIDS and Death in Europe) project, which has been running since 1997. The CASCADE project partners are monitoring people with well-estimated dates of seroconversion – this is defined as the moment when HIV antibodies can first be detected in the blood, and usually occurs within three months of exposure to the virus. By studying people whose seroconversion dates are known, the partners are able to track the progress of the disease from the very beginning and investigate which factors affect survival.
‘We have been able to document, in the absence of therapy, what matters and what doesn’t matter in determining survival,’ explained Kholoud Porter of the UK Medical Research Council’s Clinical Trials Unit, which is coordinating the project.
Dr Porter said that without therapy, average survival times decline steadily with age. Someone infected in their early 20s could expect to live for an average of 14 years, while someone infected in their 50s faced an average survival time of just six years. These findings have practical implications for treatment, as they can help clinicians decide whether a patient should start taking therapy or not.
In total the project is tracking over 17,000 people across Europe. As well as looking at the impact of age on survival, the project partners are also studying gender differences and would like to do more work on differences in survival between different ethnic groups.
The project has also explored the impacts of therapy on survival. With the advent of therapy, people are living longer, often in excess of 20 years. ‘We now expect that 10 years after infection, 90% of people will still be alive,’ said Dr Porter.
One interesting finding from the project is the fact that therapy benefits older people more than younger people. Although this appears counterintuitive, the researchers believe it could be because older people are better at adhering to their therapy and following medical advice. Therapy also benefits women more than men, probably for similar reasons.
As therapies become more effective, and survival time increases, it is likely that more HIV positive people will die of non-AIDS causes. However, as Dr Porter pointed out, although people are living longer, they do not have a good immune status. She is particularly concerned that there will be an increase in cancers. Furthermore, many people with HIV are co-infected with Hepatitis C, making them more prone to liver disease.
However, even as therapies extend the survival times of people with HIV, the project partners are increasingly worried about forms of HIV which are resistant to existing therapies. In particular they are monitoring the extent of transmitted drug resistance across the population and working to understand its consequences on therapy.
An area of particular interest for the project is Central and Eastern Europe. The project has partners in four countries in the region: Russia, Ukraine, Poland and Estonia. While many western European countries have been tracking cohorts of people with HIV for many years, in Eastern Europe there is no tradition of establishing and following cohorts.
A major aim of the project is to build research capacity in the region, and to this end the project is training researchers there to carry out tests like the STARHS assay. STARHS stands for Serologic Testing Algorithm for Recent HIV Sero-Converters, and as the name suggests, it shows whether someone was infected with HIV recently or a long time ago. Those who are identified has having been recently infected can then be enrolled in a cohort to track the progress of the disease in people in those countries.
The project is funded in its current form until 2010, but Dr Porter hopes it will be able to continue beyond then, and extend its reach further into Eastern Europe. Meanwhile it will continue to provide an essential overview of the factors influencing the survival of the growing numbers of people in Europe who are living with HIV.
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Data Source Provider: Based on CORDIS News interview with CASCADE Project Coordinator
Document Reference: Based on CORDIS News interview with CASCADE Project Coordinator
Subject Index: Coordination, Cooperation; Medicine, Health; Scientific Research